Impact of Se concentration and distribution on topological transition in FeTe1-xSex crystals

A topological transition in high-temperature superconductors FeTe1-xSex, occurring at a critical range of Se concentration x, underlies their intrinsic topological superconductivity and emergence of Majorana states within vortices. Nonetheless, the influence of Se concentration and distribution on the electronic states in FeTe1-xSex remains unclear, particularly concerning their relationship with the presence or absence of Majorana states. In this study, we combine density functional theory (DFT) calculations, pz-dxz/yz-based and Wannier-based Hamiltonian analysis to systematically explore the electronic structures of diverse FeTe1-xSex compositions. Our investigation reveals a nonlinear variation of the spin-orbit coupling (SOC) gap between pz and dxz/yz bands in response to x, with the maximum gap occurring at x = 0.5. The pz-pz and dx2-y2-pz interactions are found to be critical for pd band inversion. Furthermore, we ascertain that the distribution of Se significantly modulates the SOC gap, thereby influencing the presence or absence of Majorana states within local vortices

Cultural Distance between China and US across GLOBE Model and Hofstede Model

This study focuses on the comparison of cultural distance between China and US across GLOBE (the Global Leadership and Organizational Behavior Effectiveness) Model and Hofstede Model. Research in the cultural distance between the two countries has always been a hot topic in international business field. This paper first gives a brief introduction of GLOBE Model and Hofstede Model, and compares the cultural distance between China and US from the 9 dimensions in GLOBE Model and the 5 dimensions in Hofstede Model, and then compares the different results yielded. Finally a way forward in the future research is suggested, and some issues for further research into this fundamental area of international business are canvassed.Key words: Cultural distance; GLOBE Model; Hofstede Model; China; U

Modeling of biomass accumulation and filter bed st6ructure change in biofilters for gaseous toluene removal

[Abstract] In this study, a proper microbial growth model was established and analyzed to investigate the biomass accumulation process in biofilters. Four biofilters treating gaseous toluene were set up in parallel and were operated under different inlet toluene loadings for 100 days. Based on the experimental data of microbial biomass and toluene removal rate, the kinetic parameters were decided by either estimation from literature or parameter regression. The calculation results based on the model showed a good agreement with the experimental data of biomass change. By applying the model, it is found that lower than 50% of biomass in the filter bed was active during the last 50 days for the four biofilters. In addition, the void fraction of the filter bed with highest loading was only 55% of the initial level at the end of the operation. All the experimental and calculation results indicated that the microbial growth model could successfully describe the biomass accumulation process and have the potential to predict the long-term performance of biofilters

Optimizating Drilling Operating Parameters With Real-Time Surveillance and Mitigation System of Downhole Vibration in Deep Wells

Torsional vibration is the main bottleneck which leads to low efficiency of rock breaking. According to the characteristics of torsional dysfunctions performance, the paper defines three main types of stick-slip, and analyzed the relationship between ROP and energy from bit. Based on Newton’s equations of motion, established frequency domain, single degree of freedom, damped and forced drill string torsional vibration prediction model, with more accuracy for downhole drill string mechanical state description. On this basis, semi-analytical transfer matrix method is adopted to establish drill string response relationship between internal force wave and surface parameters changes in the condition of vibration, which greatly reduce the number of discrete elements and the associated computing time, enabling rapid screening of a large number of design alternatives on a PC. In addition, the response parameters for drillstring stick-slip are integrated into an index (Vibration Strength Estimate, VSE), which is used to quantitatively evaluate downhole stick-slip severity. A three-week pilot test has been conducted in deep wells in Yumen Oilfield in China, with 25% increase of the average ROP and 40% enhancement of the average bit footage compared with offset wells. Validation of field application shows that the downhole torsional vibration evaluation technology is an effective method for further excavate the potential of ROP and reduce drilling cost

Direct single-molecule dynamic detection of chemical reactions.

Single-molecule detection can reveal time trajectories and reaction pathways of individual intermediates/transition states in chemical reactions and biological processes, which is of fundamental importance to elucidate their intrinsic mechanisms. We present a reliable, label-free single-molecule approach that allows us to directly explore the dynamic process of basic chemical reactions at the single-event level by using stable graphene-molecule single-molecule junctions. These junctions are constructed by covalently connecting a single molecule with a 9-fluorenone center to nanogapped graphene electrodes. For the first time, real-time single-molecule electrical measurements unambiguously show reproducible large-amplitude two-level fluctuations that are highly dependent on solvent environments in a nucleophilic addition reaction of hydroxylamine to a carbonyl group. Both theoretical simulations and ensemble experiments prove that this observation originates from the reversible transition between the reactant and a new intermediate state within a time scale of a few microseconds. These investigations open up a new route that is able to be immediately applied to probe fast single-molecule physics or biophysics with high time resolution, making an important contribution to broad fields beyond reaction chemistry

Revisions about Government Subsidy Disclosures and Investors’ Response to Earnings Reports: Evidence from the 2017 Government Subsidy Disclosures

We examine whether the quality of information in earnings reports, as indicated by the earnings response coefficient (ERC) decreases when the measurement and disclosure of government subsidy has been changed by revising accounting standards. According to the old accounting standards in China, the gains from government subsidy should be reflected in “non-operating” income. However, the newly revised accounting standards regulates that a part of government subsidy can be reflected in the report item of “other income” in under the operating income item. We use 2017 revisions of accounting standards in China as an instrument to capture a change in the position of financial statements where the government subsidy is revealed. Employing a difference-in-differences design and exploiting the adoption of the new accounting standards, we find a statistically and economically significant decrease in ERC for treated firms relative to controlled firms. Our findings represent the first empirical evidence that the change of government disclosures can negatively affect the information content of earnings report

Molecular Dynamics Simulation of Chain Folding for Polyethylene Subjected to Vibration Excitation

We propose a molecular dynamics method with vibration excitation, named as VEMD, to investigate the vibration effect on chain folding for polymer molecule. The VEMD method is based on the introduction of periodic force, the amplitude and frequency of which can be adjusted, and the method was applied to the folding simulation of a polyethylene chain. Simulation results show that the vibration excitation significantly affects the folding of the polyethylene, and frequency and amplitude of the vibration excitation play key roles in VEMD. Different frequencies and amplitudes will determine how and to what extent does the vibration excitation affect the folding process of the polyethylene structure

New results for fractional ordinary differential equations in fuzzy metric space

In this paper, we primarily focused on the existence and uniqueness of the initial value problem for fractional order fuzzy ordinary differential equations in a fuzzy metric space. First, definitions and relevant properties of the Gamma function and Beta function within a fuzzy metric space were provided. Second, by employing the principle of fuzzy compression mapping and Choquet integral of fuzzy numerical functions, we established the existence and uniqueness of solutions to initial value problems for fuzzy ordinary differential equations. Finally, several examples were presented to demonstrate the validity of our obtained results